Science Siftings

New Zealand Tablet, 23 November 1911, Page 2387

Science Siftings

By ‘ Volt.’

Preservation of Wood. During the year 1910, according to the official report just published by U.S. Department of Forestry, 63,266,271 gallons of creosote and 16,802,502 gallons of zinc chloride were consumed in impregnating woods to prolong their lifetime. The zinc chloride used was exclusively a domestic product, whereas the greater part of the creosote was of European importation. Approximately 100 million feet of timber was treated. The creosote treatment was by far the more popular.' Bursting Steel. An experiment that demonstrated the capacity of steel to endure greater pressure than the hardest stone was made in Germany. Corundum was chosen for the stone, and small cubes of both substances were placed under pressure. A weight of six tons smashed the corundum, but forty-two tons were required to crush the steel. When the steel did give way the effects are described as remarkable. With a loud explosion the metal flew into powder, and its sparks are said to have bored minute holes in the crushing machine. An Early Airship. In 1834 a dirigible balloon, 130 feet long, endeavored to fly from France to England. The itinerary, from Champ de Mars to London, was mapped out with great precision, and a multitude gathered to watch the start. The machine failed utterly, whereupon the crowd demolished it in anger. The craft had the form of a monster seafish and was inflated with hydrogen. Within was a second envelope, which, with the aid of pumps, compressed or rarefied the air for ascending or descending as might be desired. There was no motor, and the navigators were to work the steering ■machinery by hand. The wicker car was built to hold ten persons. This was probably the earliest of airships of the Zeppelin type. Aids to Astronomy. Spiders as an aid to astronomy are recognised to such an extent that certain species are cultivated solely for the fine threads they weave. No substitute for the spider’s thread has yet been found for bisecting the screw of the micrometer used for determining the positions and motions of the stars. Not only because of the remarkable fineness of the threads are they valuable, but because of their durable qualities. The threads of certain spiders raised for astronomical purposes withstand changes in temperature, so that often in measuring sunspots they are uninjured when the heat is so great that the lenses of the micrometer eyepieces are cracked. These spider lines are only one-fifth to oneseventh of a thousandth of an inch in diameter, compared with which the threads of the silkworm are large and clumsy. Paper Cones for Cups. As part of the campaign against the common drinking cup and the diseases which it spreads, a health commissioner suggests the use of paper cones for cups in the absence of an individual cup of more pretentious material. He said that in the schools of Austria the children were taught to carry several sheets of writing paper in their pockets at all times. Then, when a child was thirsty, he could roll one of the sheets into a cone and make a perfectly serviceable cup which could be placed after being used in the nearest waste-paper box. How to roll the cones deftly was taught the children. The tearing cf a notch about half an inch long near one end before rolling the cone serves to make the improved cup stronger.